I have already finished
modifications
colours
scripts for transport and work with AI helper checked in field 47 (in AI mode the width is limited to 12 meters) in manual mode more options
bugs
there is no model image in the store since the crash…

It seems like the joint in the liner is not unlocked. Try to collapse and extrude it again and see if it is better. I would guess that this is a savegame problem where the liner isn't properly restored after loading.